Enter a value and select Convert.
How to use this converter
Enter a signed decimal where allowed, then select Convert or press Enter. Comma decimals and expressions are rejected rather than guessed. Copy produces a plain conversion statement without promotional text.
Definition and review
Constants follow NIST Guide to the SI, Appendix B.8. Values are calculated locally; raw numbers are not uploaded, stored, placed in URLs, or included in analytics.
Common millimeters conversions
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 mm | 0.03937007874 in |
| 5 mm | 0.1968503937 in |
| 10 mm | 0.3937007874 in |
| 25.4 mm | 1 in |
| 50 mm | 1.968503937 in |
| 100 mm | 3.937007874 in |
| 254 mm | 10 in |